A green building is energy efficient, resource efficient and environmentally responsible…

Calling a building green in SA, up until now, has been taken more or less at face value; those with a little bit of savvy are able to scrutinise the details more closely, but most people just have to take the developer's word for it. Not a great rating system.

But the Green Building Council of SA (GBCSA) developed a rating tool for public comment on their website – www.gbcsa.org.za. Today is the last day for comment and the end of the pilot period of the rating tool. The GBCSA really want individuals and organisations to comment and will be using the feedback to influence any changes they make to the tool. Called the Green Star SA – office rating tool, it’s for use by new office construction projects and base building refurbishments. But when is a building considered green... and what does the council consider green elements? The building needs to include:

• careful building design to reduce heat loads, maximise natural light and promote the circulation of fresh air
• environmentally friendly, non-toxic materials
• reduction of waste and re-cycled materials
• water-efficient plumbing fittings and water harvesting
• renewable energy sources

Which buildings in SA are deemed green

BPs Southern Africa head office CT
(I know, they’re an oil company, but BP’s head office is on the cutting edge of green in SA)

When BP’s Southern Africa head office in the Victoria and Albert Waterfront in Cape Town was designed, its annual energy consumption target was set at 115kWh/m² and 10 percent of the overall energy had to come from renewable resources. Key to this was the shading and insulation of the building.

“Solar water heaters on the roof supplement hot-water cylinders and photovoltaic cells on the roof and entrance canopy ... can generate 10 percent of peak electricity demand.

“The roof garden’s moderating effect on climate by retaining heat energy from the sun rather than reflecting it and, through evaporation of moisture, helps to cool the air, therefore saving on air-conditioning and heating costs,” BP says.

The aim was to get water consumption to 25 percent lower than that of an equivalent conventional building. To this end, rainwater from the roof, condensed water from the air-conditioning units and 30 percent of water run-off from showers and hand-wash basins, are stored in a grey-water tank and used to flush toilets and irrigate gardens.

WesBank and FNB homeloans’ new headquarters Jhb
Anyone who’s driven past this monstrosity might disagree with its environmental claims, on the grounds that its nothing short of a massive strain on the eye, but the company makes a couple of green claims:

The energy demand of is 10 percent less than that of most other buildings in South Africa, the company says.

Solar energy is used for the water-heating system in some areas of the building. Insulation measures have resulted in a 10 percent saving in electrical demand for the building, says architect Kim Fairbairn.

The air-conditioning economy cycle ensures a 33 percent kWh saving, the company says.

“Condensate from the air-conditioning – roughly five swimming pools’ worth of water daily – are collected and used to irrigate the surrounding landscape.”

Storm water collects in a pond, preventing flooding of the river which runs past the premises, and greatly reducing soil erosion on the riverbanks.

Woolworths’ Midrand distribution centre is “green from top to bottom”, according to Richard Inskip, executive director of operations at the retailer.

“During the environmental impact study, prior to the building of the centre, the endangered African bullfrog was discovered on the site. Planning of the development was carefully managed to protect these frogs and maintain their natural habitat around the huge water collection ponds on site.”

Grey water is used to flush toilets. Rain water is stored to use for irrigation and all other water supplies are drawn from boreholes. With a building that size the danger of creating an “urban heat island” existed, which means the building would reflect heat rather than absorb it as agricultural land would. The solution: planting grass on the roofs of selected areas.

Woolworths has calculated:

• The grey-water system cost R300000 and saves R30000 annually (10-year payback)
• Borehole pumps cost R250000 and save R125000 annually (two- year payback)
• Solar heating for ablution facilities cost R230000 and save R25000 per year

via [dispatch]